Technical Field
The present invention relates to a method for producing bearing shells of plain bearings. It also relates to a bearing shell produced by using such a method.
It is known that two-component aluminum bearing shells used in engines of motor vehicles, for example, are subject to fatigue. Such bearing shells consist of a steel back and a bearing metal layer applied thereto by means of a roll bonding process, which can consist of an aluminum-tin alloy, for example. A further intermediate metallic layer can be inserted between the steel back and the bearing metal layer in order to improve the mechanical properties of the bearing shell.
However, due to the production process of such a composite material and also due to the mechanical properties of the bearing metal, the bearing shells configured in this way are restricted in their stress capacity to loads in the engine of up to approximately 70 MPa.
To generate increased fatigue strength in shafts, gear wheels, springs or also connecting rods, the surfaces thereof are bombarded by steel, ceramic and/or glass beads in accordance with the state of the art (so-called “shot blasting”). By this, compressive residual stresses are generated in the near-surface area, which lead to increased fatigue strength by strain hardening.
Related Art
DD 259 021 A1 discloses a journal bearing of reciprocating compressor driving gears. Here, a journal bearing designed as a composite bearing is described, which is configured with regard to the geometry thereof such that a defined compressive pretension develops in the sliding layer by installation into a housing and the consequential deformation. By this, the resilience of the bearing can be increased.
Alternatively, DE 10 2007 028 888 A1 discloses the targeted mechanical strain hardening of areas of a crankshaft, i.e. a component supported by a bearing, in order by this to increase the strength of this component. This effect is therefore substantially similar to that of DD 259 021 A, however with this effect relating to the strain hardening of a component supported by a bearing (in contrast to a bearing shell).
DE 10 2005 055 708 A1 relates to a method for forming cavities by blasting abrasive particles.